Recommended Posts

I am considering buying a GS 450h but one thing puzzles me - why are some adverts, for instance on the Lexus used car website, listing the 450h as either 291 bhp, or 345 bhp. I can't see anything thats differentiates the cars except for the years, but even then that is not apparently the reason.

Is this someone adding the electric motor output to the petrol engine output, and if so why would Lexus use two different output figures on their own site. Or, could some models have a factory bhp upgrade ?

Parkman.

Share this post


Link to post
Share on other sites
 

The answer is simple: 291 hp are from only petrol engine, while 345 is the equivalent combined power of petrol and electric engines. And to complicate the calculus,  electric motors have specs of max 200 hp, but the combined power is NOT the sum of both power sources.

For sure, GS 450h is a fast car.

  • Like 5

Share this post


Link to post
Share on other sites
1 minute ago, Zotto said:

The answer is simple:

.. snap.. faster then me :yucky:

 

Share this post


Link to post
Share on other sites

Thanks for the reply, I wondered if the combination of the two figures was the answer. But then I wonder why isn't there a common value when advertising the car ? When it was straight-forward "bhp" it was simple, even with supercharged or turbocharged engines. The engine produced 100, 200, or 300 bhp or whatever.

Why is the electric engine limited to 200 hp, and how does this compare to bhp ? Tesla P90 S is all electric but you can buy the upgrade to give the car 690 bhp.

Could have anything to do with trying to hoodwink insurance companies ? You tell the the engine power is 290 bhp, when it is really 350 bhp but the extra doesn't count !!!!

I think that there should be advertising laws that stipulate you have to declare the full car's output including every means of motive power to give a true overall figure. Then at least you know what you are dealing with.

Just a quick aside, but on the same matter - what is the full figure for a Lexus IS 300h ? is it 181 bhp, can anyone tell me ?

Parkman.

Share this post


Link to post
Share on other sites
9 minutes ago, parkman said:

Thanks for the reply, I wondered if the combination of the two figures was the answer. But then I wonder why isn't there a common value when advertising the car ? When it was straight-forward "bhp" it was simple, even with supercharged or turbocharged engines. The engine produced 100, 200, or 300 bhp or whatever.

Why is the electric engine limited to 200 hp, and how does this compare to bhp ? Tesla P90 S is all electric but you can buy the upgrade to give the car 690 bhp.

Could have anything to do with trying to hoodwink insurance companies ? You tell the the engine power is 290 bhp, when it is really 350 bhp but the extra doesn't count !!!!

I think that there should be advertising laws that stipulate you have to declare the full car's output including every means of motive power to give a true overall figure. Then at least you know what you are dealing with.

Just a quick aside, but on the same matter - what is the full figure for a Lexus IS 300h ? is it 181 bhp, can anyone tell me ?

Parkman.

All electric motors have a a design maximum output that if exceeded leads to burnt out winding's in the motor. So the electric motor is not limited in it's output in the normal sense used for petrol engines.

The main drive motor MG2 (motor generator 2) is electrically rated at 140kw (140,000 watts). A hp is 746 watts giving the motor an output of 180 hp.

The problem is the motor has to get an electrical supply of 140kw to give the hp output. This could come from the Battery, and although it is capable of this output it only has enough capacity at that output for about 20 seconds. The supply then has to come from MG1 (motor generator 1)  this is rated at substantially less than MG2, and gets its mechanical power from to provide electricity from the engine.

This is why the output of the engine and electric motor cannot be added together as as the engine has to split it's output between driving the wheels, and MG1 to drive MG2 that also drives the wheels. The transmission is sometimes called a power split devise for this reason.

John.

John

  • Like 2

Share this post


Link to post
Share on other sites

2 hours ago, parkman said:

Tesla P90 S is all electric but you can buy the upgrade to give the car 690 bhp.

This is worth a watch ...

 

 

Share this post


Link to post
Share on other sites

Many thanks, John [Britprius] for a very good explanation of the hybrid system. I had read a couple of times that the IS 300h hybrid Battery will only drive the car for a couple of minutes before it is depleted, perhaps less than that.

Again thanks for the post.

I will have a watch of the Tesla video - and then go and buy a new P90S with the 600 bhp upgrade................................... I don't think :wallbash:

Parkman.

Share this post


Link to post
Share on other sites
18 hours ago, parkman said:

Many thanks, John [Britprius] for a very good explanation of the hybrid system. I had read a couple of times that the IS 300h hybrid Battery will only drive the car for a couple of minutes before it is depleted, perhaps less than that.

Again thanks for the post.

I will have a watch of the Tesla video - and then go and buy a new P90S with the 600 bhp upgrade................................... I don't think :wallbash:

Parkman.

It does make you think when a Tesla can do 350 miles and a 450h only 1mile on a full charge.

Share this post


Link to post
Share on other sites

30 minutes ago, stevet said:

It does make you think when a Tesla can do 350 miles and a 450h only 1mile on a full charge.

In GS we got like just over 1KWh usable while Tesla got 85KWh :)

I can do  more than a mile. Just accelerate to 30mph and try to keep that speed up on the Battery only - you will further than 1 mile.

  • Like 1

Share this post


Link to post
Share on other sites
On 2/20/2018 at 3:44 PM, parkman said:

I think that there should be advertising laws that stipulate you have to declare...

I believe that is exactly the current case that advertising laws stipulates that only the main engine power should be advertised. Furthermore, there are no single agreed methodology which could be used to calculate combined electric + petrol power. As such 345hp figure is just Lexus marketing language, but they would risk being sued if somebody would find that to be less based on different methodology. That is why they keep it a bit vague "car engine produced 290hp and combined electric and petrol power is "equivalent" to 345hp". Nowhere they say it is 345hp, but it is equivalent based on their own methodology, which is not explained. The confusion appears when whoever sells the cars chooses to follow either marketing information, or official information from car's technical description.

  • Like 1

Share this post


Link to post
Share on other sites
4 hours ago, Hangie said:

I can do  more than a mile. Just accelerate to 30mph and try to keep that speed up on the Battery only - you will further than 1 mile.

More to the point, after another few miles you will be 'recharged' and you can then do another mile on 'electric power' with no plug-in required. On a long journey you can travel many miles on 'electric power' in a hybrid - there is no fixed 'electric range' at all. Of course, in a hybrid it's not really electric power anyway - it's just petrol power (with a bit of help from the regen) that's been converted into electricity. 

Comparing the electric 'range' of standard hybrids with a BEV (or even a PHEV) is all a bit pointless really. They're completely different concepts.

  • Like 2

Share this post


Link to post
Share on other sites
On 21/02/2018 at 7:52 PM, Ten Ninety said:

More to the point, after another few miles you will be 'recharged' and you can then do another mile on 'electric power' with no plug-in required. On a long journey you can travel many miles on 'electric power' in a hybrid - there is no fixed 'electric range' at all. Of course, in a hybrid it's not really electric power anyway - it's just petrol power (with a bit of help from the regen) that's been converted into electricity. 

Comparing the electric 'range' of standard hybrids with a BEV (or even a PHEV) is all a bit pointless really. They're completely different concepts.

 

Exactly... which is why on my average for this week over 320 miles is 48mpg (according to the trip computer) ... which isn't bad for the size of engine.  It is interesting watching how the electric motor is used to supplement the engine at 70mph on slight hills. 

Share this post


Link to post
Share on other sites

On 20/02/2018 at 3:44 PM, parkman said:

Just a quick aside, but on the same matter - what is the full figure for a Lexus IS 300h ? is it 181 bhp, can anyone tell me ?

Total system output is 223 hp, the petrol engine can deliver 181 hp. This is fully disclosed by Lexus GB in the specifications of the vehicle.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now